Apparatus for producing artificial respiration



Dec. 3, 1940.

R. M. -'McMlLLlN APPARATU$ FOR PRODUCING ARTIFICIAL RESPIRATION Filed Dec. 51, 1937 Patented Dec. 1940 PATENT OFFICE APPARATUS FOR PRODUCING ARTIFICIAL RESPIRATION Robert M. McMillin, Detroit, Mich. I Application December 31. 1931, Serial No. 182,898

3 Claims.

This invention relatesto apparatus for producing artificial respiration, or "artificial lung, wherein a hood or casing is placed over the intenmediate body portion of a patient with a space 5 between the body and hood in which sub and super atmospheric pressure is alternately established to induce or promote breathing.

The invention includes amongits objects: To provide an artificial lung of such construction as will permit the patient or userto assume difierent or varying postures while using the l n 4 To provide apparatus of this type wherein a relatively high or line degree of control may be 15 exercised over the artificial breathing action, so

as to obtain the most eflicient respiration in accordance with the individual characteristics a of the patient-or user of the lung;

To provide adjustable automatic regulation for 20 fine pressure and suction phases of the apparaus;

To provide an artificial lung which is not only more comfortable to the user, but which is so constructed as to permit an attendant or nurse 25 to gain access to the interior of the lung while the latter is in use: and,

To generally improve apparatus of this class.

The foregoing and other objects and advantages will become apparent in view "of the follow- 30 ing description taken in conjunction with the drawing, wherein: v

Fig. 1 is a view in elevation; ofapparatus embodying features of the present invention;

Fig. 2 is a substantially ,central sectional view 35 of an automatic control and regulating unit forming part of the apparatus;

Fig. '3 is a detailed sectional view showing one of the valves in the air lines leading to the said I control unit; I 40 Fig. 4 is asubs'ta tially central cross section of the lung proper; and,-

Fig. 5 is a longitudinal sectional view of a modified type of lung.

Referring to the drawing in detail, and par- 45 ticularlyto. Fig. 1, an air pump is generally indicated at 5, andis shown as of the electrically operated type and accordingly is provided with leads 3 adapted to be connected to or plugged intoa suitable source of current supply. The pump 50 is connected through pipes I and 8 with a suction or vacuum tank 3 and a pressure tank In.

The tanks 3 and I 8 communicate through pipes II and i2 with a main flexible hose or air line connection through an automatic control and 55 regulating unit generally indicated at I! and shown more or less in detail in Fig. 2. The pipe the diaphragm .32

lines II and I2 are provided with orifice valves Ha and'l5, for a purpose which will be hereinafter specified.

Referring now particularly to Fig. 2, it will be 5 noted that the housing for the unit ll provides a closed pressure chamber l6, and the pipe lines II and I2 communicate with this chamber through valve ports I! and I8, respectively, formed with valve seats "a and "la. A reciprocating valve 10 guide stem I9 is provided and has at opposite ends thereof closure members, or valves proper 20 and 2|. The stem or rod I3 is mounted for sliding movement in a. guide bracket 22, which may be projected from the end wall of the main housing. Automatic valve actuating mechanism is provided and in the example shown comprises links 23 and 24, stem 25 adjustable through nut 25a, spring 26 and guide rod 21. The rod 21 is mounted to reciprocate in upper guide bracket 28, which is adjustable through the medium of guide 29,. and a lower bearing or bushing 30, which is adjustable through medium of nut 3!. A valve actuating diaphragm 32 is provided and the rod 21 is connected to said diaphragm, tension springs 33 and 34 being disposed on said rod above and below' the diaphragm. The tension of springs 33 and 34 may be adjusted through the medium of. wing nuts 23 and 3l-, respectively. Below the dia phragm, is a vent chamber 35, the wall of which is provided with one or more air vents 36. The links 23. and 24 are pi tally connected at their inner ends to the lower gmd of the stem or rod 25,

while the outer or rem e ends of said links are pivotally connected to the valve stem or guide I9 35 and the diaphragm connecting rod 21.

A gauge 31 is preferably mounted in operative communication with the chamber ii, to indicate at all times thepressure in said chamber. It is also preferred to provide gauges 38 and 33 in the 40 pipe lines II and i 2 respectively, so as to give a visible indication of the pressures in said lines during operation of the apparatus.

The control mechanism just described operates as follows: 43

The'valves 20 nd 2 I' move in unison, their position as shown indicating that the pressure or compression phase is being carried out, the valve 2| clearing the pressure port l8 and valve 23 closing the suction port 11. 7 When pressure builds up inthe chamber i6 and consequently in the line 13 to the lungproper, to be described, I

7 will be depressed past dead' center, at which time the spring 28 will also move past dead center or below the pivotal axis of the be accurately regulated to obtain the most ef' fective respiratory action for the patient being.

links 23 and 24, thereby automatically throwing the valve 2| against the seat I81: and unseating the valve 20 from the seat Ila. The suction phase will then commence,-and suction will then build up in the chamber I6 and main conduit or line l3 until a certain predetermined subatmospheric pressure is reached, at which time the diaphragm 32 and valves 20 and 2| will be returned to the respective positions shown in the drawing. By adjusting the tension of the springs 33 and 34, the throw of the diaphragm 32 may treated.

The valves Ma and I5 have a particular function to perform, these valves Controlling the speed and time of the suction and pressure intervals. In other words, by varying the orifice openings'controlled by these valves, the time lengths of the suction and compression intervals as well as the speed of the latter may be regu-' lated in the suction and compression lines II and I2, without varying the motor speed as in certain conventional types of apparatus.

The lung proper, in its preferred form, comprises'a casing 40 of suitable resilient or flexible material, such as rubber, composition rubber and fabric, or the like which is held in expanded or hood-shaped position through the medium of stays or hoops 4|. Suitable means are prefer ably provided to maintain the hoops r stays in fixed spaced relation, such means in the form shown comprising a backing strip 42, preferably of material having sufiicient body to hold the hoops in position while at the same time permitting a limited amount of bending or fiexing of the lung. This strip also forms a support or brace for the patient. In the instance shown, the strip 42 is made of relatively hard or solid rubber having the hoops embedded therein. The opposite ends of the lung may be sealed to the patients body through the medium of suitable tape or the like as indicated at 43 and 44. The line I3 communicates with the lung through a sealed connector such as the coupling 45 constructed to permit more or less free rotation of the hose coupling.

With this type of resilient lung, the patient may either lie' down on a table or other support, as is customary in the conventional rigid type of lung, or the patient may adopt varying postures, such as a sitting, or partially reclining position; or the patient may stand and walk within the limits of the conduit l3.

Means are provided whereby access may be had to the interior of the lung or hood without I breaking the seal'of the latter, such, for instance,

as where a nurse orattendant desires to wash the patient. Such means in the form shown comprises a flexible sleeve 46, note particularly Figs. 1 and 4, having its outer end normally sealed by a cap 41. The sleeve 46 may be joined in sealed relation or vulcanized to the casing or hood 40 or it may be made integral therewith.

Whenever it is desired to gain access to the interior of the lung, the cap 41 may be removed or partially removed and the arm of the attendant inserted in the -sleeve 46 and the end of the -sleeve taped or otherwise sealed to the arm,

whereupon the operation of the apparatus may be resumed, or the sleeve may be applied without disturbing the normal operation of the apparatus.

Patient to inhale.

Fig. shows a type of lung wherein springs are utilized for'exhausting air from the patients lungs. In this instance, the casing or hood is indicated at 4011 and is provided with a plurality of springs 48 having their lower ends seated on a backing member or analogous strip 49. The remaining parts of the lung may be A constructed as in Fig. 1, the difference in this surplus capacity on both the compression and.

depression strokes to take care of maximum requirements, and that constant pressure regulating valves be provided to maintain a constant pressure in tank l0 and sub-atmospheric pressure in tank 9, such pressure being registered by gauges 38 and 39. As will be understood, the pump 5 supplies fresh air to the pressure tank and thus to the lung and skin of the patient.

It will be seen from the foregoing that I have provided respiratory apparatus having certain important advantages not only as to control but also as to use and which facilitates both the most efficient or efiective breathing of the. patient and comfort of the latter.

It will be understood that the foregoing description and illustration in the drawing is more or less illustrative, and that certain changes in construction, design and operation may be adopted within the scope of the invention as defined by the appended claims.

I claim: v

1. In apparatus for inducing artificial respiration, an artificial lung in the form of a flexible casing adapted to be applied over a portion of the body of a patient, means sealing the upper and lower portions of said casing to the patients body, a series of annular supporting members in said casing maintaining the latter distended from at least a portion of the Datients body, and

body, a series of hoops .in said casing maintaining the latter distended from at least a portion of the patients body, and means having a limited amount of flexibility extending along the back of the casing for holding said hoops in spaced relation along the length of the casing.

3. In apparatus for inducing artificial respiration, an artificial lung in the form of a casing adapted to be applied over a portion of the body of a patient, means maintaining said casing distended providing. an air space between the body of the patient and wall of the casing, spring means in said casing adapted to compress the patients abdomen and cause the patient to exhale, and means for creating suction in said casing to compress said springs and permit the ROBERT M. McMILLIN. 

